Pyramid of the Sun built by Aztecs in the ancient city of Teotihuacan, outside Mexico City, Mexico

View of the Aztec-built Pyramid of the Sun in the ancient city of Teotihuacan, outside Mexico City, Mexico. It is the third largest pyramid in the world. Stairs lead to the top. View of sacrificial altar where human sacrifices were offered. Various Aztec idols on pedestals, displayed for tourists. A large stone calendar (the Piedra Del Sol) used by the Aztecs, with two guards standing by.